I know this has been suggested countless times, but it is a huge annoyance to me and a lot of other people, and it's gone unfixed for a long time now!
The Mantis Hive is one of the most popular group dailies in my experience, it's rare to find an empty instance. And that's great! The dungeon sat mostly empty for far too long apart from the occasional person going after eggs for VTEs or one of the items that dropped in there which were mostly gimmicks and sub-par. The daily missions (as well as the tunnels and the Borealis entrance) breathed new life into the dungeon.
But this change isn't all good. The dailies have you kill a large number of mantises and smugglers, usually almost all of that particular enemy available. With the popularity of the missions, you'll almost always run into another group running the mission, and chances are the groups will be large enough that you can't just merge together. Now in most cases this isn't a big deal, just wait a few minutes, maybe grab a sandwich, a glass of water, have a cigarette, whatever and it'll be ready. However when the dungeon was updated, its spawns weren't. I'm not sure exactly how long it takes for things to respawn, but it's at least 15 minutes, and given how easy it is for groups to step on one anothers' toes things get bogged down really fast.
So how do we fix this? Well, I see two potential solutions. First is the easiest, just increase all the spawn rates. The enemies can be calmed and rooted, and there are mantises running everywhere at all times, so I don't think fast repops would hamper anyone's progress and yet it would alleviate the traffic jams that are so common! Another solution that would require some careful thought and maybe even map edits would be to increase the number of each daily mission monster available. The problem with this one is that crowding the dungeon will cause it to present a lot more challenge, upsetting the ability for people to do it on-level. There are a lot of 220s that cruise through the place, but there are plenty of people who do it at lower levels too, we don't want to squash their enthusiasm!
To get a bit more nebulous about the issue, I think it breeds a bit of an atmosphere of contempt, selfishness, and unhelpfulness. I see a lot of lowbies begging for help with the ravagers daily, and personally while I usually love helping people out, I tend to ignore them because it's such an awful mission purely because of the traffic issues. In addition, inside the dungeon itself there's rarely much negotiation or talking, just a lot of stealing kills and screwing over each other because "if I can't have an easy win nobody can", or at least that's the way it comes across. I know it annoys everyone involved, and most of the people would be nice and fun to play with in any other situation. My point is that I just don't think the situation is good for the game or the community.
Anyway, I think this nano-mantis is finally about to respawn, so I'll end this post here!
Edit:
Some lengthy posts have been exchanged and I think the important outcome is a new suggestion that may work better than either speeding up spawns or adding more. The playfield could be split into an instanced and public version similar to Pandemonium. The entrance from Borealis and the one-room exit from the Smuggler's Den could be used to create a staging area where you choose between the instanced and open playfields. The entrance in SFH could simply remain an entrance to the public version. This would neatly solve the issues, but would at the same time be less asocial than simply instancing it completely.